roberts r



E. ROBERTS Oct. 30, 1945.

BRAKE COOLING FOR CENTRIFU GALS AND THE LIKE Original Filed Nov. 30, 1934 Reissued Oct. 30, 1945 BRAKE COOLING FOR CENTRIFUGALS AND THE LIKE Eugene Roberts, Hastings, N. Y., assignor to The Western States Machine Company, New York, N. Y., a corporation of Utah Original No. 2,096,341, dated October 19, 1937,

Serial No. 755,333, November 30, 1934. Application for reissue February 13, 1945, Serial No.

7 Claims.

This invention relates to the cooling of brake drums, such as are usually attached to the shaft of a suspended centrifugal or other machine, for the purpose of preventing excessive heating of the brake drum due to the frequent application or setting of the braking elements and is intended to provide an improved liquid cooled brake construction together with an automatic control for the liquid so that during the normal operation of the machine the heat developed by friction may be rapidly conducted away and temperature strains in the brake drum may be graduated, and so that the supply of cooling medium may be controlled so as to avoid splashing or spilling of the liquid.

In certain classes of machines, particularly machines of the type of sugar centrifugals whose cycle of operations, through the development of improvements in recent years, has been cut down to a period of only two or three minutes, the frequent starting and stopping of these heavy machines results in excessive heating of the brake drum to which the friction brake element is applied for the purpose of quickly stopping the machine. No satisfactory solution of this problem has heretofore been found.

The present invention solves this diificulty by providing apparatus to maintain a body of water in the interior of the brake drum while the machine is either rotating or at rest, and to cause a periodic interchange of cool water for heated water in this body through the action of water supply means and water removal means which operate in coordination with each other and with a phase of the successive cycles of operation of the machine.

The body of water maintained in the drum absorbs the heat generated by the brake, drawing it through the wall of the brake drum not only during but after the braking period of each machine cycle. The water body thus keeps the brake from becoming overheated and itself becomes gradually heated, thus tempering the drastic temperature changes such as otherwise would occur frequently in the drum, with a tendency to check or crack it, where the machine runs with great kinetic energy in cycles of brief duration and must be stopped by the brake in each cycle. An unchanged body of water, however, would be boiled away after a few cycles by accumulations of heat from the brake; hence cool water is supplied to the water body in a phase of each cycle, to cool down the water retained, and in addition water is discharged simultaneously from the water body in the drum so as to carry away the accumulated or excess heat absorbed from the previous braking operation, and also so as to prevent the volume of the water body retained fromexceeding the amount that will be held by the drum during its rotation.

Should the latter occur water would spray or splash around the machine with the result of damaging equipment, wetting operators and falling into the sugar or other material being treated.

This coordinated supplying of cool water and discharging of heated water occur in regular periods or phases of the successive machine cycles lying between the successive braking operations of the machine, and thus they gradually bring the brake drum back to a normal temperature before it is called upon to act again. A system of continuous water supply and continuous water removal, on the other hand, would not be practical for sugar centrifugals of standard type because of the frequent starting and stopping of these machines and the changed speed and other conditions thus entailed, and because of the weakening or complication of the brake or associated structures which sucha system would entail.

An illustrative embodiment of this invention will be described in the following specification, while the invention itself will be defined in the claims hereto annexed.

In the drawing I have illustrated one form of construction and arrangement embodying the principles of this invention, in' which Fig. 1 is a front elevation showing so much of a centrifugal and its driving, braking and cooling apparatus as is necessary to an understanding of this invention.

Fig. 2 is a side elevation of the control shaft as viewed from sectional plane 2-4 marked on Fig. 1.

Fig. 3 is a sectional plan view on horizontal section plane 3-3 of Fig. 1 to show the construction and arrangement of the revoluble brake drum secured to the vertical shaft of the centrifugal.

Fig. 4 is a detail view showing on an enlarged scale that portion of the cooling liquid supply pipe containing the cut off valve and the regulating valve.

The centrifugal machine to which the brake cooling appaTratus is applied in this case for purposes of illustration, comprises the usual centrifugal basket I secured to the lower end of a vertical gyratory shaft 2, that is suspended from the hanger 3 by means of the usual and well known ball and socket suspension joint. In this case the centrifugal spindle or shaft carries a belt pulley 4 around which passes a quarter turn driving belt 5, which passes from the clutch driven pulley l on themain line drive shaft 8 at the back of the machine and which passes over an.

intermediate idler pulley 6, all in accordance with well known practice in the case of belt driven machines. I 4

The belt pulley 4, as usual, is secured to apply the belt at the level of the center of gyration of the basket. Below the driving pulley is. secured a cylindrical brake drum 20",. whose bot.- tom edge is extended by means of an inwardly and upwardly turned flange 2| to form an annular channel or recess for. the reception. of the. cooling liquid. The interior spider orflange 22-, which supports the brake drum, is inclined in- =wardly and upwardly and bolted in this case securely to the bottom spider 4 of the driving pulley 6, asshown at 22. The outer".- edge. portion of. spider 2-7;- is provided. at. intervals with arcuateopenings H located: shovev the liquid re:- (IEfiVlIlgf-IBCBSS at 2!, so: that liquid flowing in to the. upper portion of the pulley can escape andrun down to the: bottom recess or chamber of the pulley without being spilled. The upper edgeof the: pulley is provided with. an annular in.- turned lip on flange 24, which serves" to-prevent; the escape of the liquid over the top when the machine is in operation. The flange 2t, therim of. drum 29 and the: inwardly and upwardly extending portions of flange 2+. form together an inwardly ands upwardlyfacing annular water.- retaining trough or receptaclev to retain a. body ofcooling liquid in the drum while it is. eithe rotating or at rest. I

The cooling liquid. is supplied bymeans of a. liquid supply Pipe 25,. which is provided with a regulating. valve 25* that can be set by hand to provide any desired rate: of of the liquid, and beyond the regulating valve 25 is: located a self-closing spring actuated valve 25 whose stem. extends upward into engagement with an overhead cam, which is secured to the. centrifugal horizon control shaft I I.

As the centrifugal control mechanism itself. is

not the invention herein. claimed, only so much of the illustrative construction as may be needed to understand the present improvement will be described. That mechanism is now known in the art and is described in the specification of .my copending United States Patent No. 2,145,633, filed June 23, 1934. As shown. in Fig. 1, the horizontal control shaft H extends alongside of the upper portion of the centrifugal in a fore and aft direction perpendicular to the driving or line shafl; i at the back of the machine. It carries a hand wheel ll at the front end and is supported in front and rear stationary aligned bearing members H Intermediate of its ends it carries a loose sleeve l4, around which is coiled a helical spring I whose forward end is anchored to the stationary supporting bearing H and whose rear end is secured to a circumferentially adjustable tensioning nut M mounted on the sleeve. To the sleeve is also rigidly secured a disc l4 having a projecting pin engaged by a shoulder on a cam-like disc I which is pinned to the shaft ll. Secured to the rear end of this shaft is a pinion I2 intermeshing with a toothed arcuate sector member l3 forming part of to. clutch shipper fork l3, which is fulcrumed at I 3" to shift to and fro a clutch controlling sleeve 8 slidably keyed to the line shaft 8. It W ll S fflce to say that when the control shaft I l is rotated clockwise it acts, through the shipper fork connection l3, to throw the clutch from the position shown in Fig. 1, and places the centrifugally actuated clutch shoes in active position withtrespect to; the driving pulley T online shaft 8, and the clockwise movement of the shoulder on disc H also turns the sleeve [4 to a position where the brake is held inactive against the torsion of spring M This operation occurs, as is: well known, in connection with starting the running, or sugar treating period of each cycle of operation of the machine. The reverse or count'erclockwise, rotation of the shaft ll, induced by the helical spring M and the pin on disc l4 whenv the drive and brake control is released from itsclutch engaging position, causes the clutch to become inactive and the brake to become. set to stop the machine.

The brake setting occurs because at the for-. ward. end of. the sleeve l4 there is. secured theretoa lever l5 having lin-k. connections at, [6 and li with an. arm. I! secured to a brake spindle F8, to which are secured toggles I! in such relation: that movement of the brake spindle l8 one direction as induced byspring M contracts the. friction shoes; 25, forming the braking element, upon the. brake, drum 20-.

About midway of the; centrifugal; control shaft.

H is: secured a cam 2& directly above the cut-off valve 25 so that, as is;- best shown in Fig. 4;, clockwise; rotation. of the control. shaft, which acts; first to release the; brake and thereafter to start the: entrifugal by throwing in; the clutch, serves also when the centrifugal is started on fast rotation to; depress. the valve 25 to open positionand allow the cool liquid-to flow throu h supply pipe 2.5; to the interior of the pulley. The:

fast rotation. of. the. centrifu al causes the-liquid in the. pulley or drum to build. up in a. rin likc well against the inside of the brake drum 2E1. as indicated, by vertical dotted line in Fig. 1..-

Atav convenient distance inwardirom the inside face of the brake drum 20.- and spaced above the bottom wall thereof is. located the end of a discharge or draw-off pipe. 2?, which is. turned to. face; the. direction of revolution" of the brake drum and acts as a scoop to carry off the excess of water beyond a predetermined vertical line, so that not only is the liquid prevented from overflowing or escaping from the pulley other wise than through the. pipe, but since the water heated by contact with the drum becomes less dense than the cooler entering water and there! fore moves to the inside, this off-take pipe 26 serves to remove the heated water and retain a supp y of cool water constantly against the innor face of the brake drum. Accordingly, the heat is continuously abstracted from the water body in the brake drum while the'machine is in operation; and when the machine stopsthe liquid then' collects and; is retained in the receptacle of the drum, where it continues to draw heat from the. drum, while at the. same time through the counterclockwise. rotation of the cut off device 28 the supply of water is cut. off due to the vfact that the same rotative movement .of the sleeve M and control shaft II that releases the clutch and sets the brake acts through device 28 to allow the spring applied to the valve 25 to close the valve. The hand valve 25 permits complete e ulation of the supply of cooling liquid- The above arrangement not only provides .a very effective and simple means for rapidly conducting away the heat developed by the friction of the brake element on the brake drum, but it provides a fool-proof arrangement preventing the spilling of the liquid away from the machine or into the basket by reason of the fact that when the machine is running the off-take pipe 26 will limit the accumulation of liquid to a predetermined point, while on the other hand the very act of throwing out the clutch and setting the brake necessarily results in cutting off any further supply of liquid. The body of liquid retained inside the brake drum or rim after the supply has been cut off prevents overheating of the drum by drawing heat from its inner face as long as a temperature difference exists. The flow of c001 liquid into this body and in intimate contact with the inner face of the drum or rim during a subsequent running of the machine, together with the concurrent removal of heated liquid from the body through the off-take 26, completely cools the body of the liquid and the rim to a normal operating temperature before the next brake operation occurs and generates more heat.

The body of water constantly maintained inside the brake drum prevents overheating of the drum, the brake linings and the bearings of the centrifugal spindle, and reduces destructive thermal shocks in the drum that otherwise result from the frequent stopping of high speed or heavy-duty centrifugal machines. If the cool water supply inadvertently should not function this water body also serves as a safety factor, enabling the brake to be operated several times before overheating can occur, and warning the machine attendant, by the emission of steam, that the system requires attention. The systems herein disclosed have the further practical advantage of avoiding the spilling or splashing of water into the centrifugal away from the brake drum of the machine.

It will be understood of course, that the invention is not restricted to use on a vertical shaft nor to these special features of construction and operation that are of particular utility-in the centrifugal field, the true measure of the invention being the spirit of the disclosure and the requirements of the claims but not the illustrative details mentioned hereinabove.

What I claim is:

1. A centrifugal machine having a central basket shaft provided with a driving pulley and a brake drum having an annular trough for cooling liquid adjacent the inner periphery thereof, means including a control shaft by which the energizing of the driving pulley and the energizing of the brake is alternatively effected, and means for supplying cooling liquid into said trough, said liquid supplying means being responsive to movement of said control shaft to supply liquid while the driving means is active and to cut off the liquid supply when the brake is active.

2. A liquid cooled brake including a brake rim and means forming with said rim an inwardly facing annular trough for retaining a body of liquid inside the rim while the same is rotated, means for supplying cooling liquid into said trough. means for drawing off excess liquid during rotationof the rim to maintain a predetermined volume of liquid therein, and means for interrupting the operation of said liquid supplying means before the rim is brought to rest.

3. A liquid cooled brake drum adapted for attachment to a vertical shaft, said drum being provided with means at top and bottom defining an basket or elsewhere inwardly facing annular trough for retaining a body of liquid inside the drum while thedrum is either rotating or at rest, means for drawing off excess liquid to maintain a predetermined volume of cooling liquid inside the brake drum while the shaft is rotating, and means for cutting off a fresh supply of liquid to the drum when the brake is applied.

4. A water cooled brake system for a cyclically operated centrifugal machine comprising a brake drum attached to the vertical shaft of the machine and constructed as an annular receptacle to hold a body of water effective for cooling the drum while it is either rotating or at rest, said drum including a rotatable brake flange and a cylindrical brake rim thereon formed at the top with an inwardly directed flange and at the bottom with an inwardly directed imperforate bottom wall having an upwardly directed extension in spaced relation to said rim defining therewith and with said bottom wall an inwardly and upwardly facing annular water-retaining trough for so holding said body of water, water supply means including a conduit extending into said trough and periodically operative inflow control means for periodically supplying cool water through said conduit to the body of water inside said drum in each of the successive machine cycles, and means operative concurrently with said water supplying means for removing heated water from said body, said removal means comprising an oiltake conduit extending into said trough to a predetermined position spaced from said rim and said bottom wall to take off water from said drum as the body of water therein exceeds a predeterminedvolume effective for cooling and within the water-holding capacity of said drum.

5. A water cooled brake system for a suspended cyclical centrifugal machine comprising a brake drum attached to the vertical shaft of the machine and constructed as an annular receptacle to hold a body of water effective for cooling the drum while it is either rotating or at rest, said drum including a rotatable brake flange and a cylindrical brake rim thereon formed: at the top with an inwardly directed flange and'at the bottom with an inwardly directed imperforate bottom wall having an upwardly directed extension in spaced relation to said rim defining therewith an inwardly and upwardly facing annular trough for retaining the body of water against the inside of the rim while the drum is either rotating or at rest, water-supply means including an inflow conduit extending into saidtrough and inflow control means connected with said conduit operative periodically intermediate the successive braking operations of the machine to supply cool water through said conduit into the drum to cool the body of water therein, and means operative intermediate the successive braking operations of the machine and concurrently with the operation of said supply means to remove heated water from the drumfsaid removal means comprising an ofl'take conduit extending into said trough to a position so predetermined so as to remove from said trough only such water as exceeds a predetermined volume adequate for cooling and within the water-holding capacity of the drum.

6. A water cooled brake system for a suspended cyclical centrifugal machine comprising a brake drum attached to the vertical shaft of the machine formed with an inwardly facing annular trough to hold a vertical annular wall of water during each running period of the machine and m mm a. g 0 th water hil the machine 3 m an r nde ed op r v in:- co d na ion with, the stazyting of eaeh running period and rendered inoperative. in coqrdingtioh with each br n e q of t e e in to supply 001, wat r; into; the d um o s to 0 .01 t e dy of water therein, and means opepative. during each nning pe q t move heated a r and; vent sgillingof. excess water from the rotating (1mm and to limit the body of water retained therein t um h n h ati ate -ho in ca acity o said; hann '7. A cyclically. operated centrifugal maclflne c mpr ing h cemb nat on of a us nd ask sha mv ded wi h a dri i means and a r k ha ing a brake 1 m 1 sa d h f orm d a geceptqagle to retain a, body of water in the drum eiiectjve. fer cpeling the same while the drum; is either rotating o a re a d dru in din a rotata e take la ge and, cylindr cal b ake tin; he eo te m d at h to with an nwardly direc d an u ar fla e and an hehot m w th an inward sr di ec e m r v at bot o Wal having an upwardly directed annular exteneipn in with em in upward fac n expande channel:

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